| /* |
| * Copyright 2018 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| #ifndef NATIVEOBOE_OSCILLATORBASE_H |
| #define NATIVEOBOE_OSCILLATORBASE_H |
| |
| #include "AudioProcessorBase.h" |
| |
| constexpr float TWO_PI = (float)(2.0 * M_PI); |
| |
| class OscillatorBase : public flowgraph::AudioProcessorBase { |
| public: |
| OscillatorBase(); |
| |
| virtual ~OscillatorBase() = default; |
| |
| void setSampleRate(float sampleRate) { |
| mSampleRate = sampleRate; |
| mFrequencyToPhaseIncrement = 1.0f / sampleRate; // scaler |
| } |
| |
| float setSampleRate() { |
| return mSampleRate; |
| } |
| |
| /** |
| * Control the frequency of the oscillator in Hz. |
| */ |
| flowgraph::AudioFloatInputPort frequency; |
| |
| /** |
| * Control the linear amplitude of the oscillator. |
| * Silence is 0.0. |
| * A typical full amplitude would be 1.0. |
| */ |
| flowgraph::AudioFloatInputPort amplitude; |
| |
| flowgraph::AudioFloatOutputPort output; |
| |
| protected: |
| float incrementPhase(float frequency) { |
| mPhase += frequency * mFrequencyToPhaseIncrement; |
| // Wrap phase in the range of -1 to +1 |
| if (mPhase >= 1.0f) { |
| mPhase -= 2.0f; |
| } else if (mPhase < -1.0f) { |
| mPhase += 2.0f; |
| } |
| return mPhase; |
| } |
| |
| float mPhase = 0.0; // phase that ranges from -1.0 to +1.0 |
| float mSampleRate = 0.0f; |
| float mFrequencyToPhaseIncrement = 0.0f; // Scaler for converting frequency to phase increment. |
| }; |
| |
| |
| #endif //NATIVEOBOE_OSCILLATORBASE_H |